tbuckley/cabot-search huggingface dataset:
Abstract 1028: Phosphate dysregulation as a novel therapeutic strategy in ovarian and uterine cancers
Authors: Daniel Bondeson, Brenton Paolella, Adhana Asfaw, Michael Rothberg, Thomas Skipper, Gabriel Mesa, Alfredo Gonzalez, Lauren E. Surface, Kentaro Ito, Mariya Kazachkova, William N. Colgan, Allie Warren, Joshua Dempster, J Michael Krill-Burger, Maria Ericsson, Andrew Tang, Iris Fung, Emily S. Chambers, Mai Abdusamad, Nancy Dumont, John Doench, Federica Piccioni, David Root, Jesse Boehm, William C. Hahn, Michael Mannstadt, James McFarland, Francisca Vazquez, Todd Golub
Journal: Cancer Research (2022)

Abstract Precision medicine promises to improve the treatment of cancer patients, but a lack of therapeutic targets and associated predictive biomarkers limit this reality. To identify novel strategies, we integrate genome-scale CRISPR viability screens across many cancer models with cellular and molecular features to systematically define The Cancer Dependency Map. Using this data, we have identified that XPR1, an inorganic phosphate exporter protein, is a highly selective dependency gene in ovarian and uterine cancers. These cancers are sensitive to loss of XPR1 due to over-expression of SLC34A2, a phosphate importer protein. These data suggest a synthetic lethal relationship in which intracellular phosphate homeostasis is dysregulated in cancer. As proof-of-concept of pharmacological inhibition of XPR1, we have developed protein ligands based on the receptor binding domain of viruses which use XPR1 for cellular entry. These ligands inhibit XPR1 and kill cancer cells in an on-mechanism manner, but may be limited in their clinical utility. As such, we are deepening our understanding of the mechanisms of XPR1-dependent phosphate efflux, and have identified a novel partner protein that is integral to phosphate efflux, possibly revealing functional domains that small molecule inhibitors might target. Overall, these data highlight a novel mechanism to treat cancers by leveraging cancer-specific phosphate dysregulation and further reinforce the Cancer Dependency Map as a powerful engine to uncover novel therapeutic vulnerabilities. Citation Format: Daniel Bondeson, Brenton Paolella, Adhana Asfaw, Michael Rothberg, Thomas Skipper, Gabriel Mesa, Alfredo Gonzalez, Lauren E. Surface, Kentaro Ito, Mariya Kazachkova, William N. Colgan, Allie Warren, Joshua Dempster, J Michael Krill-Burger, Maria Ericsson, Andrew Tang, Iris Fung, Emily S. Chambers, Mai Abdusamad, Nancy Dumont, John Doench, Federica Piccioni, David Root, Jesse Boehm, William C. Hahn, Michael Mannstadt, James McFarland, Francisca Vazquez, Todd Golub. Phosphate dysregulation as a novel therapeutic strategy in ovarian and uterine cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1028.
Abstract 2678: LLL12B, a novel small molecule STAT3 inhibitor induces apoptosis and suppresses cell migration and tumor growth in triple-negative breast cancer cells
Authors: Li Pan, Xiang Chen, Feyruz V. Rassool, Chenglong Li, Jiayuh Lin
Journal: Cancer Research (2022)

Abstract Persistent STAT3 signaling has been recognized as a cancer therapeutic target in some cancer types including triple-negative breast cancer, and the development of effective small molecule STAT3 inhibitors for potential cancer therapy is desirable. In this study, we tested a novel oral bioavailable small molecule STAT3 inhibitor, LLL12B in MDA-MB-231, SUM159, and 4T1 triple-negative breast cancer cells. Triple-negative breast cancer cells frequently express persistent STAT3 phosphorylation and its cell viability is sensitive to STAT3 knockdown by siRNA. LLL12B selectively inhibited IL-6 mediated induction of STAT3 phosphorylation but had little effect on IFN-γ mediated induction of STAT1 phosphorylation or EGF mediated induction of ERK phosphorylation. LLL12B inhibited STAT3 phosphorylation, induced cell apoptosis, and reduced cell colony formation in triple-negative breast cancer cells. In addition, LLL12B inhibited cell migration of triple-negative breast cancer cells. Furthermore, LLL12B suppressed tumor growth of MDA-MB-231 triple-negative breast cancer cells in a mammary fat pad syngeneic mouse model. Together, our findings suggest that targeting persistent STAT3 signaling pathway by novel small molecule LLL12B may be a potential approach for triple-negative breast cancer therapy. Citation Format: Li Pan, Xiang Chen, Feyruz V. Rassool, Chenglong Li, Jiayuh Lin. LLL12B, a novel small molecule STAT3 inhibitor induces apoptosis and suppresses cell migration and tumor growth in triple-negative breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2678.
Abstract 1822: Selective inhibition of ZCCHC11/ZCCHC6 TUTases with genetic and pharmacological tools supports a role in glioblastoma cell growth
Authors: Robinson Triboulet, Khikmet Sadykov, Jessica L. Johnson, Andrew R. Snyder, Sarah K. Knutson, Pavan Kumar, Christopher B. Mayo, Dillon Hawley, Andrew Madanjian, Ross L. Stein, David M. Wilson, Darren M. Harvey, Shomir Ghosh, Robert M. Campbell
Journal: Cancer Research (2022)

Abstract The purpose of the study was to determine if genetic and pharmacological inhibition of terminal uridyltransferases (TUTases) ZCCHC11 and ZCCHC6 could modulate Glioblastoma (GBM) cell growth in vitro. ZCCHC11 (also known as TUT4 and TENT3A) and ZCCHC6 (also known as TUT7 and TENT3B) catalyze uridylation of diverse RNA species. Recent evidence indicates that genetic perturbation of ZCCHC11/6 expression can disrupt cell proliferation of both immortalized and patient-derived primary GBM cell lines (Kim et al., Mol Cell 2020). We confirmed that genetic inhibition of ZCCHC11/6 with siRNA or CRISPR can decrease viability of U-87 MG and A-172 GBM cell lines, and we identified DK-MG as another GBM cell line with sensitivity to ZCCHC11/6 knockdown. Herein, we report the first novel, potent, and selective inhibitor of ZCCHC11/6, TS-1. Biochemically, TS-1 can block ZCCHC11/6-mediated uridylation of an RNA substrate in vitro (IC50 = 0.65 nM for recombinant ZCCHC11 protein; IC50 = 9.6 nM for recombinant ZCCHC6 protein). ZCCHC11/6 inhibitor TS-1 could decrease cell viability in U-87 MG, A-172 and DK-MG cells (cell viability IC50s ranging between 0.7-1.5 μM) and induce apoptosis and cell cycle arrest. A cellular assay detecting uridylation of miR-191 as a marker for ZCCHC11/6 activity was developed and validated. TS-1 strongly decreased uridylation of miR-191 in U-87 MG, A-172 and DK-MG cells (IC50 ranging between 10-40 nM). In contrast, TS-2, a weakly active enantiomer of TS-1 (enzyme IC50 = 0.15 μM and 1.8 μM against ZCCHC11 and ZCCHC6, respectively), had less impact on cell viability, apoptosis, cell cycle and uridylation in cells. In conclusion, we have verified ZCCHC11/6-dependency in a set of GBM cell lines and we have also developed a first-in class potent and selective small molecule that reduces in vitro Glioblastoma cell proliferation through selective inhibition of TUTases activity. Citation Format: Robinson Triboulet, Khikmet Sadykov, Jessica L. Johnson, Andrew R. Snyder, Sarah K. Knutson, Pavan Kumar, Christopher B. Mayo, Dillon Hawley, Andrew Madanjian, Ross L. Stein, David M. Wilson, Darren M. Harvey, Shomir Ghosh, Robert M. Campbell. Selective inhibition of ZCCHC11/ZCCHC6 TUTases with genetic and pharmacological tools supports a role in glioblastoma cell growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1822.
Abstract 1892: Expression of bacterial heme-sequestering proteins (HeSPs) in <i>Pichia pastoris</i> for effective treatment of lung cancer
Authors: Narges Salamat, Adnin Ashrafi, Tianyuan Wang, Zakia Akter, Hanling Gong, Li Zhang
Journal: Cancer Research (2022)

Abstract Heme is a central biosynthetic molecule with important implications in diverse molecular and cellular processes, including oxygen utilization and metabolism. Heme carries out a vital role in mitochondrial energy generation through oxidative phosphorylation (OXPHOS) by acting as a cofactor or prosthetic group for complexes II, II, and IV in the electron transport chain. Lung cancer is the leading cause of cancer related death in the US. Our lab has previously shown that non-small cell lung cancer (NSCLC) cells exhibit an elevated heme flux characterized by elevated heme synthesis and import. This increased heme flux correlates with an enhanced oxygen consumption and ATP production. To target this elevated heme flux, we have engineered recombinant bacterial HasA hemophores as heme-sequestering proteins (HeSPs). HeSPs bind to and sequester heme with an extremely high (pM) affinity, thereby disrupting this elevated heme flux. HeSPs display potent anti-tumor activity in mouse models of NSCLC and triple-negative breast cancer (TNBC). Here, we utilized the Pichia pastoris expression platform to achieve high-yield expression. P. pastoris is a methylotrophic yeast that has minimal endogenous protein secretion and potentially high-yields for heterologous protein expression, due to a tightly regulated alcohol oxidase gene (AOX1). The P. pastoris expression platform is generally easier to handle and requires simpler fermentation conditions than mammalian cell cultures, making it an ideal candidate for expression of recombinant bacterial proteins without endotoxin contamination.We utilized a secretion signal to direct secretion of HeSP2 into the culture medium to allow for easier protein purification. Purification was performed through ion exchange chromatography. We utilized native PAGE and heme-binding spectrum to verify that these yeast-expressed HeSPs adopt a similar conformation to those expressed in bacteria and maintain their heme-binding activity. HeSPs expressed through this P. pastoris expression system demonstrated remarkable anti-cancer efficacy in proliferation assays on NSCLC cells and SCLC (small cell lung cancer) cells. Experiments are underway to test their anti-tumor efficacy in mouse models. These experiments may suggest a novel approach to generate effective anti-cancer agents. Citation Format: Narges Salamat, Adnin Ashrafi, Tianyuan Wang, Zakia Akter, Hanling Gong, Li Zhang. Expression of bacterial heme-sequestering proteins (HeSPs) in Pichia pastoris for effective treatment of lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1892.
Abstract 3872: Overexpression of miR-200 in cancer-associated fibroblasts suppresses the migration and invasion of cancer cells in co-culture systems
Authors: Inyoung Cheon, Sieun Lee, Young-Ho Ahn
Journal: Cancer Research (2022)

Abstract Cancer-associated fibroblasts (CAFs) promote cancer progression and metastasis in the tumor microenvironment. CAFs are regulated by diverse processes including regulation by microRNAs (miRNAs). To profile miRNAs involved in the regulation of CAF activation, we performed the NanoString nCounter® assay in mouse CAFs and normal lung fibroblasts (LFs). Among the miRNAs differentially expressed between CAFs and LFs, miR-200 family members were significantly downregulated in CAFs. Overexpression of miR-200 in CAFs suppressed the migration and invasion of lung cancer cells in co-culture systems (transwell migration and spheroid invasion assays). Next, we tried to identify novel miR-200 target genes based on RNA sequencing data obtained from control and miR-200-overexpressed CAFs, lung adenocarcinoma TCGA data, and TargetScan. We are now studying on these candidates to see whether they are involved in the interaction between CAFs and cancer cells.On the basis of these findings, we conclude that miR-200 suppresses the interaction between CAFs and lung cancer cells in the tumor microenvironment. Keywords: cancer-associated fibroblasts, miR-200, lung cancer, tumor microenvironment, invasion Citation Format: Inyoung Cheon, Sieun Lee, Young-Ho Ahn. Overexpression of miR-200 in cancer-associated fibroblasts suppresses the migration and invasion of cancer cells in co-culture systems [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3872.
Abstract 1864: Baicalein attenuates endometrial cancer growth by suppressing the ARF6
Authors: Latoya Mcglorthan, Viqar Syed
Journal: Cancer Research (2022)

Abstract Using mass spectrometry-based proteomics, we have previously shown enhanced expression of the Adenosine diphosphate-Ribosylation Factor-6 (ARF6) in endometrial cancer cell lines compared to immortalized EM-E6/E7-TERT endometrial epithelial cells. ARFs belong to the RAS superfamily of small GTPases. ARF family proteins are activated by Guanine nucleotide Exchange Factors (GEFs) and inactivated by GTPase-Activating Proteins (GAPs). When active, they bind effectors, which mediate downstream functions. ARF6 localized on the plasma membrane plays a role in actin cytoskeleton dynamics and endocytic recycling. Dysregulation of expression and/or activity of ARF6 has been associated with enhanced cell migration, invasion, and proliferation in several types of cancer. Knockdown of ARF6 significantly inhibited the invasiveness of the cancer cells. There is a critical need for novel promising anticancer agents with lesser side effects and higher efficacy. Baicalein, extracted from the roots of the Chinese herb Huang Qin (Scutellaria baicalensis), showed a significant anticancer impact on many human cancers. However, the specific molecular mechanisms are still nebulous. Endometrial cancer cell lines were exposed to different concentrations of baicalein for 24 to 120 h. The effect on cell proliferation and invasion was determined utilizing MTS and Boyden chamber assays, respectively. The baicalein induced a dose and time-dependent reduction in cell viability. The invasiveness of cells was attenuated by baicalein. Furthermore, the anticancer effects were mediated by decreased ARF6, Rac1, and PAK1 expression in baicalein-treated cancer cells. In summary, the data reveal that suppression of ARF6 could reduce the invasive potential of endometrial cancer by modulating the major downstream effectors Rac1 and PAK1. Citation Format: Latoya Mcglorthan, Viqar Syed. Baicalein attenuates endometrial cancer growth by suppressing the ARF6 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1864.
Abstract 713: Monoclonal antibodies for the detection of the uropathogenic specific protein (USP): A bacterial genotoxin linked to colorectal cancer
Authors: Rachell Martínez-Ramírez, Valeria Toro-Díaz Toro-Díaz, Pearl Akamine, Kimberly Ruiz-Rosado, Ignacio Pino, Abel Baerga-Ortiz
Journal: Cancer Research (2022)

Abstract The Uropathogenic Specific Protein (USP) is an E. coli genotoxin nuclease primarily associated with urinary tract infections. Previous efforts in our laboratory found the USP gene in stool samples; more frequently found in stool samples from adenoma and CRC patients than in samples from healthy individuals. New efforts in our laboratory aim to find the USP protein in the same population of patient samples and this may require anti-USP antibodies, which at present are not commercially available. In this work, we report the first anti-USP monoclonal antibodies (mAbs) for the detection of USP in human samples. A total of 38 hybridoma supernatants containing mAbs were assayed by immunoblotting and biolayer light interferometry (BLI) for their ability to recognize purified USP(∆HNH). Results from BLI showed that the pair AB-A10 and AB-D5 presented the highest affinity with slow dissociation, moving forward for the development of a sandwich ELISA. Using AB-A10 as the capture antibody, and AB-D5 as the top antibody, results from the ELISA showed signals that were concentration-dependent above 6 ug/mL of USP. We also used the AB-D5 and AB-D10 in immunoblots for the detection of USP in proteins extracted from stool samples of patients with adenoma and CRC. The immunoblots reveal the detection of a 25 kDa protein that remains unidentified but is present only in some of the samples. This could be the first detection of USP protein directly in a biological sample. Efforts are underway to identify this protein band and confirm its identity as USP. Additional efforts are aimed at increasing the number of stool samples analyzed to establish whether USP protein is a risk factor for CRC or adenoma. Citation Format: Rachell Martínez-Ramírez, Valeria Toro-Díaz Toro-Díaz, Pearl Akamine, Kimberly Ruiz-Rosado, Ignacio Pino, Abel Baerga-Ortiz. Monoclonal antibodies for the detection of the uropathogenic specific protein (USP): A bacterial genotoxin linked to colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 713.
Abstract 4217: MEKi in combination with anti-OX40 generates metabolically fit effector CD8+ T cells, enhances stem cell-like memory CD8+ T cells, and leads to strong anti-tumor activity
Authors: Pankaj Gaur, Vivek Verma, Mays Alreem Elayyan, Zainab Ramlaoui, Simon T. Barry, Viia E. Valge-Archer, Paul D. Smith, Seema Gupta, Samir N. Khleif
Journal: Cancer Research (2022)

Abstract In the tumor microenvironment (TME), T cell exhaustion and short persistence of effector cells are crucial factors that limit the efficacy of endogenously generated or adoptively transferred effector cells. Regenerative stem-cell memory CD62LhiCD44lowSca1+ CD8+ CD8+ T cells (TSCM) persist longer and produce cells with more vital effector functions. OX40, a member of TNFRSF4, has been shown to promote the expansion and proliferation of activated effector T cells, leading to the generation of robust anti-tumor responses and immune memory. However, treatment with anti-OX40 as a single therapeutic modality has not generated desirable clinical outcomes. A combination of immune modulators has been found to enhance the therapeutic efficacy synergistically. Recently, we reported that inhibition of MEK1/2 using selumetinib (AZD6244) leads to a significant increase in the numbers of CD8+ TSCM cells with self-renewability, enhanced multipotency and proliferative capacity, leading to potent anti-tumor effects. Therefore, here we combined selumetinib with anti-OX40 to investigate if enhanced immune-mediated anti-tumor responses could be obtained. Using three mouse tumor models (TC1, B16, and CT26), we found that combination of MEKi with anti-OX40 enhances the anti-tumor activity by increasing the expansion of total and antigen-specific CD8+ T cells in the TME. These CD8+ T cells have higher functional activity as seen by increased Granzyme B and INF-γ production. We also found similar results after adoptive cell therapy (ACT) where infusion of MEKi-treated cells in B16 tumor-bearing mice synergized with anti-OX40 agonist treatment. Interestingly, anti-OX40 treatment of MEKi-treated CD8+ T cells enhanced the metabolic fitness as demonstrated by low mitochondrial potential and enhanced Oxygen Consumption Rates (OCR), Spare Respiratory Capacity (SRC), and Extra-cellular Acidification Rates (ECAR) compared to anti-OX40 treatment alone. Furthermore, OX40 agonist significantly enhanced the longevity of MEKi-induced CD8+ TSCM cells. In summary, our data provide a novel strategy to utilize MEKi to enhance the efficacy of ACT and combination immunotherapy using anti-OX40 agonist. Citation Format: Pankaj Gaur, Vivek Verma, Mays Alreem Elayyan, Zainab Ramlaoui, Simon T. Barry, Viia E. Valge-Archer, Paul D. Smith, Seema Gupta, Samir N. Khleif. MEKi in combination with anti-OX40 generates metabolically fit effector CD8+ T cells, enhances stem cell-like memory CD8+ T cells, and leads to strong anti-tumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 4217.
Abstract 1482: Efficient targeting of prostate cancer using ligand conjugated and chemically modified tumor suppressive miRNA
Authors: Ahmed M. Abdelaal, Sudarshan Kasireddy, Ikjot S. Sohal, Philip S. Low, Andrea L. Kasinski
Journal: Cancer Research (2022)

Abstract MicroRNAs (miRNAs) inhibit the expression of genes through imperfect base pairing with target messenger RNAs (mRNAs), which allows a single miRNA the ability to regulate the expression of multiple genes, potentially acting as a multi-drug cocktail. In principle, tumor-suppressive miRNAs, such as miRNA-34a (miR-34a) are excellent anti-cancer agents; however, due to toxicity associated with currently used delivery vehicles and poor in vivo miRNA stability, the clinical application of miRNAs is thwarted. To overcome these challenges, we engineered two modifications to the miRNA. The first entails conjugating the miRNA to a ligand that promotes delivery specifically to cancer cells while the second involves using a fully chemically modified miRNA (FM-miR) to enhance miRNA stability. The ligand chosen for delivery, 2- [3-(1,3-dicarboxy propyl) ureido] pentanedioic acid (DUPA), is a high-affinity binding partner of the Prostate-Specific Membrane Antigen (PSMA), which is significantly upregulated on prostate cancer cells. We show that DUPA-miR-34a is specifically targeted to tumor cells overexpressing PSMA, is rapidly internalized by the cells, and induces target gene silencing. The binding and uptake of miR-34a by the tumor cells is dependent on conjugating the miRNA to DUPA. In vivo, DUPA-conjugates bind specifically to PSMA expressing prostate tumors with no significant uptake from normal organs or tumors with no PSMA expression. Additionally, Incorporation of the ionophore nigericin in the DUPA ligand enhances miR-34a silencing activity through facilitating its endosomal escape. However, since RNAs are inherently unstable a second modification was engineered to enhance the miRNA stability. Modifying miRNA through the inclusion of phosphorothioate linkages and 2′-fluoro and 2′-O-methyl modified ribose bases, enhances miRNA stability without compromising its activity. Fully modified miR-34a (FM-miR-34a) exhibits enhanced silencing activity of its target genes such as MET, and CD44 in comparison to partially modified miR-34a (PM-miR-34a). In addition, both PM-miR-34a and FM-miR-34a significantly inhibit cell proliferation in vitro, and the silencing of target genes requires the presence of argonaute 2 (AGO2) protein. We plan to identify the targeting differences between FM- and PM-miR-34a and will combine the DUPA ligand with FM-miR-34a to enhance both delivery and activity of miR-34a. Citation Format: Ahmed M. Abdelaal, Sudarshan Kasireddy, Ikjot S. Sohal, Philip S. Low, Andrea L. Kasinski. Efficient targeting of prostate cancer using ligand conjugated and chemically modified tumor suppressive miRNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1482.